/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.jasper.compiler;

import java.io.IOException;
import java.io.PrintWriter;

/**
 * This is what is used to generate servlets.
 * 
 * @author Anil K. Vijendran
 * @author Kin-man Chung
 */
public class ServletWriter {
	public static int TAB_WIDTH = 2;
	public static String SPACES = "                              ";

	// Current indent level:
	private int indent = 0;
	private int virtual_indent = 0;

	// The sink writer:
	PrintWriter writer;

	// servlet line numbers start from 1
	private int javaLine = 1;

	public ServletWriter(PrintWriter writer) {
		this.writer = writer;
	}

	public void close() throws IOException {
		writer.close();
	}

	// -------------------- Access informations --------------------

	public int getJavaLine() {
		return javaLine;
	}

	// -------------------- Formatting --------------------

	public void pushIndent() {
		virtual_indent += TAB_WIDTH;
		if (virtual_indent >= 0 && virtual_indent <= SPACES.length())
			indent = virtual_indent;
	}

	public void popIndent() {
		virtual_indent -= TAB_WIDTH;
		if (virtual_indent >= 0 && virtual_indent <= SPACES.length())
			indent = virtual_indent;
	}

	/**
	 * Print a standard comment for echo outputed chunk.
	 * 
	 * @param start
	 *            The starting position of the JSP chunk being processed.
	 * @param stop
	 *            The ending position of the JSP chunk being processed.
	 */
	public void printComment(Mark start, Mark stop, char[] chars) {
		if (start != null && stop != null) {
			println("// from=" + start);
			println("//   to=" + stop);
		}

		if (chars != null)
			for (int i = 0; i < chars.length;) {
				printin();
				print("// ");
				while (chars[i] != '\n' && i < chars.length)
					writer.print(chars[i++]);
			}
	}

	/**
	 * Prints the given string followed by '\n'
	 */
	public void println(String s) {
		javaLine++;
		writer.println(s);
	}

	/**
	 * Prints a '\n'
	 */
	public void println() {
		javaLine++;
		writer.println("");
	}

	/**
	 * Prints the current indention
	 */
	public void printin() {
		writer.print(SPACES.substring(0, indent));
	}

	/**
	 * Prints the current indention, followed by the given string
	 */
	public void printin(String s) {
		writer.print(SPACES.substring(0, indent));
		writer.print(s);
	}

	/**
	 * Prints the current indention, and then the string, and a '\n'.
	 */
	public void printil(String s) {
		javaLine++;
		writer.print(SPACES.substring(0, indent));
		writer.println(s);
	}

	/**
	 * Prints the given char.
	 * 
	 * Use println() to print a '\n'.
	 */
	public void print(char c) {
		writer.print(c);
	}

	/**
	 * Prints the given int.
	 */
	public void print(int i) {
		writer.print(i);
	}

	/**
	 * Prints the given string.
	 * 
	 * The string must not contain any '\n', otherwise the line count will be
	 * off.
	 */
	public void print(String s) {
		writer.print(s);
	}

	/**
	 * Prints the given string.
	 * 
	 * If the string spans multiple lines, the line count will be adjusted
	 * accordingly.
	 */
	public void printMultiLn(String s) {
		int index = 0;

		// look for hidden newlines inside strings
		while ((index = s.indexOf('\n', index)) > -1) {
			javaLine++;
			index++;
		}

		writer.print(s);
	}
}
